1. Field of the Invention:
The present invention relates in general to a hand-truck or cart device for dispensing pavement repair materials, and in particular to a heated cart for forming a liquid or semi-liquid from an asphaltic/polymeric material used to repair cracks and fill channels in pavement and the like.
2. Description of the Prior Art:
In the past, as many as three vehicles were sometimes needed to repair openings and potholes in asphalt, concrete and other roadway surfaces. One vehicle provided an air compressor for use with various pneumatic repair tools which were used to dress the hole, crack or cavity to be filled. Another vehicle contained liquid asphalt tack material which would be sprayed into the dressed cavity, and a third vehicle would deliver asphalt mix material to the cavity. The asphalt would then be packed, compacted and leveled by hand to complete the repair. This is highly impractical for small repairs such as cracks in pavement, or to fill expansion channels in pavement.
Several devices have decreased the number of separate pieces of equipment necessary for road repairs. U.S. Pat. No. 6,012,870, issued Jan. 11, 2000 and assigned to the assignee of the present invention, discloses such a device, wherein a heat chamber contains a mixing chamber having a mixing means, paddles, etc., that is mechanized. The entire apparatus rests upon a skid, which is then transported by a truck or trailer. Although an improvement over using a combination of devices, this apparatus is still impractical for repairing small cracks, wherein an economic advantage is to be gained in having a single person-operated device.
Another device, U.S. Pat. No. 5,98 8,935, issued on Nov. 23, 1999, assigned to the assignee of the present invention, discloses a truck-mounted asphalt mixer that utilizes a V-shaped interior wall. That device is specifically designed to operate using dry, radiant heat sources to heat the material being stirred within. This device has the advantage of using dry, radiant heat from air-heated spaces below the heating chamber, but has the disadvantage of being large and highly mechanized, thus impractical for small jobs.
U.S. Pat. No. 4,196,827, issued Apr. 8, 1980, entitled xe2x80x9cPortable Machine For Transporting Heated Asphalt Products For Use In Repairing Asphalt Pavementxe2x80x9dshows a portable machine which was designed to incorporate all phases of the pavement repair into one mobile unit. The machine has a hopper for transporting asphalt mix, and a reservoir below the hopper having a heat source. The reservoir contained liquid asphalt tack material. The heat source is used to heat the liquid tack material, and the tack material is used to heat the asphalt mix in the hopper by heat transfer. Asphalt tack material is also dispensed from the tack material tank by means of spray equipment connected to a discharge valve on the rear of the truck.
In spite of being less expensive to operate in terms of material and labor, the previously described device possessed several different disadvantages. Many of these disadvantages related to the type of repair material utilized and the fact that multi-component materials were required to each job. Because multiple component materials were required for each patch job, the equipment used for transporting such components was complicated and often limited in versatility. For example, the liquid asphalt tank carried on the unit was suitable for road oils and cutbacks but was not well suited for use with asphaltic cements. Also, in the case of the device described in the ""827 patent, the liquid asphalt tank was not suited for use with asphalt emulsions, because the volatile contents of the emulsions would be driven off and dry out the materials.
U.S. Pat. No. 4,944,632, issued Jul. 31, 1990, and assigned to the assignee of the present invention showed a portable unit with a separate tack oil tank which was provided with its own heat source and which was designed to prevent phase separation of the tack oil materials. While this apparatus solved the problem of tack oil phase separation, it was still designed to be employed in a multi-component repair system.
Thus, while the various prior art pavement repair devices solved several problems, they are not suitable for both small jobs such as repairing cracks, and for applying newer, asphaltic/polymeric materials that have different physical properties from traditional asphalt/aggregate compositions. In particular, smaller, one-person operated devices have heretofore been impractical due to the need for mechanization of the prior art devices. Powerful mixers have been necessary in the prior art to mix the large quantities of aggregate and asphalt, which can be highly viscous. What is needed is a means for repairing small cracks and filling expansion joints and channels that is economical and can utilize newer materials not requiring aggregate.
It is therefore one object of the present invention to provide a means for applying a new asphaltic/polymeric material to roadways that one person can operate.
It is yet another object of the present invention to provide a simple, cost effective means of applying materials to cracks and channels in roadways and other pavement areas that require filling and repair.
It is yet another object of the present invention to provide a simple means of heating and applying asphaltic materials to roadways that does not require complex agitating or stirring mechanisms.
These and other objects are achieve by providing a portable cart for transporting and dispensing heated pavement repair materials that is capable of being moved and operated by one person, the cart applying a heated asphaltic/polymeric binder material. The cart comprises a heating chamber having an enclosed interior and providing dry radiant heat and a containment chamber located within the enclosed interior of the heating chamber, the containment chamber narrowing towards an opening. The radiant heat within the heating chamber heats the material within the containment chamber to between about 150xc2x0 C. and 210xc2x0 C. Further, the heating chamber having the containment chamber there within is located upon a hand-driven cart.
The cart further comprises a hand-operated gating means, wherein the material within the containment chamber is gravity-dispensed in a controlled manner. The cart is ideal for repairing cracks and filling expansion channels in concrete and/or asphalt roadways and driveways. The dry, radiant heat source is at least one burner fired retort tube located in the heating chamber and at least partially surrounding the containment chamber. A tank of fuel such as propane is provided on the cart, thus making the cart a self contained unit easily operated by one person.
Additional objects, features and advantages will be apparent in the written description which follows.